Thread gripping and cutting device for shoe-sewing machines



' T. H. SEELY.

THREAD GRIPHNG AND cumNG nEvloE Foa sHoE sEwlNamAcHlNEs.'

APPLICATlON FILED NOV. 2| 1916.

Patented Nov. 8, 1921.

UNITED STATES PATENT OFFICE.

Specication of Letters Patent.

Patented Nov. 8, 1921.

Application filed November 2, 1916.V Serial No. 129,093.

To ZZ @Li/tom t may concern Be it known that I, THOMAS H. SEELY, a citizen of the United States, residing at Malden, in the county of Middlesex and -State of Massachusetts, have invented certain new and useful Improvements in Thread Gripping and Cutting' Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to shoe sewing machines, and more particularly to devices for severing the thread between the work and supply at the completion of the sewing of a seam, and for holding the free end of the thread projecting from the thread handling devices during the first part of the formation of a new seam.

The objects of the invention are to improve the construction and mode of operation of thread cutting and holding devices of this character, and to produce a thread holdingdevice which may be easily adjusted for different sizes of thread, and in which the tension or friction exerted by the thread holding device on the thread may be readily regulated to insure the proper formation of the first few stitches.

With these objects in view, the features of the invention consist in certain improved constructions and new combinations of parts hereafter described and' pointed out in the claims, the advantages of which will be readily understood by those skilled in the art.

The features of the invention will be readily understood from the accompanying drawing illustrating a machine embodying the invention in its preferred form, and the following detailed description of the construction therein shown.

In the drawings, Figure l is a view in side elevation of a portion of a curved hook needle inseam shoe sewing machine embodying the invention; Fig. 2l is a view of the thread cutting and holding devices of the machine, detached from the machine, looking in the direction of the arrow a, Fig` l; Fig. 8 is a view of the thread cutting and holding devices detached from the machine, looking in the direction of the arrow b, Fig. l; and Fig. tis a sectional view taken sub- .stantiallyonfthe line avant-Fig. 3.

Devices for Shoe- The machine embodying the invention as illustrated in the drawing is a shoe sewing machine of the class employing a curved hook needle and devices coperating therewith to form a chain-stitch seam, and is designed particularly for sewing inseams of welted and turned shoes. The machine is provided with a curved hook needle 2. a thread finger 4, a looper 6, and a channel guide S, all having the same construction, arrangement and inode of operation as the corresponding parts of the machine illustrated and described in applicants prior application, Serial No. 815,127, tiled January 29th, 1914.

The thread cutting and holding devices illustrated in the drawing comprise a block l0 having an arm l2 extending therefrom and secured to the shank of the looper 6 by means of a screw 17 passed through an opening 16 in the end of the arm and threaded into the looper. Mounted on the block 10 so as toembrace the block is a U-shaped spring plate 2O having substantially parallel arms 22 and 24. The block i0 and the arm 22 of the spring plate are respectively formed with opposed thread holding jaws 26 and 28 adapted to grip and hold frictionally the end of the thread when the thread is placed between the jaws. The opposed thread holding jaws are oppositely curved to form a substantially V-shaped entrance to the opening between the thread into the contracted portion of the opening where it `may be held by the jaws. The free end of the thread projecting from the thread handling devices is inserted between the thread holding jaws before the starting of a seam. The jaw 26 holds the thread with a yielding pressure against the jaw 28, and as the seam is started., the thread slips between the jaws under the pull eX- erted von the thread by the thread handling devices. The thread end is thus maintained under Vtension by the friction of the thread kholding jaws on the thread during the formation of the first one or two stitches of a .newseam, thereby insuring the proper formation of the stitches.

In sewing machines employed upon shoe work different sizes of thread are often employedV in sewing diiferent classes of work, and in accordance with one feature of the lpresent invention-means is provided for jaws to direct the diminishing the opening Athan before.

adjusting the opening between the thread holding jaws to enable the proper tension to Vbe exerted by the thread holding jaws on the thread whatever the size of the thread. In the construction shown, an adjusting screw 30 is threaded into the block 10, and

is arranged to engage at its outer end theY inner side of the arm 22 of the spring plate 20. To enable the screw 30 to be readily adjusted, the outer yend of the screw is formed with a screw driver slot, and the arm 22 of the spring plate 20 is formed with an opening 32 opposite the screw through which a small screw driver may be inserted to adjust the screw. The position of the adjusting screw 30 determines the position of the jaw 26 of the thread holding device with relation to the jaw 28 or the width of the opening between the thread holding jaws. By turning the screw 30 in a direction to unscrew it from the block 10, the arm 22 of the spring plate is moved away from the block 10, thereby increasing the opening betweenthe thread holding jaws, and upon turning the adjusting screw in a direction to screw it into the block 10, the arm 22 moves toward the block' 10, thereby between the thread holding jaws.

As stated above, inthe operation of the thread holding devices, the thread is drawn through the jaws of the thread holding devices during the formation of the first few stitches, the friction exerted by the thread holding jaws on the thread furnishing the tension required for the proper formation of the stitches. In accordance with another feature ofV the present invention, means is provided for adjusting the pressure exerted by the thread holding jaws on the thread so that the action of the jaws may be regulated to furnish just the tension required to form and tighten the lirstafew stitches in a certain and reliable manner. 1n the present construction a second adjusting screw 37 isthreaded into the block 10 and is arranged to engage at its inner end the inner side of the arm 24: of the spring plate 20. The outer or head end of the adjusting screw 87 projects through a second opening 36 in the arm 22 of the spring plate 2O so that a screw driver may be readily inserted in the screw driver slot formed in the outer end of the screw to adjust the same. By turning the adjusting screw 37 in a direction to screw it into the block 10, the arm 24 of 'the spring plate is forced away from the block 10, thereby increasing the tension of the spring plate. This adjustment of the screw will cause the thread holding jaws to exert a greater pressure upon the thread Upon turning the adjusting screw 37 in a direction to unscrew it from the block10, the arm 24: of the spring plate will move'. toward the block 10 thereby lessening the tension of the spring plate. This will result in diminishing the pressure exerted by the thread holding jaws upon the thread.

The adjusting screw 37 also acts as a stop to limit the extent to which the thread may be inserted between the thread holding jaws.

it is to be noted that with the adjusting devices described above, the opening between the thread holding jaws may be adjusted without changing the pressure exerted by the thread holding jaws on the thread, and that the pressure exerted by the thread holding jaws onthe thread may be adjusted without changing the opening between the jaws.

T he thread cutting device for severing the hread between the shce and the supply consists of a cutting blade 38 formed upon the arm 22 of' the spring plate and arranged at an angle to the plane of said arm, as shown in Figs. l and 2. The edge of the cutting blade is directed away from the opening between the thread holding jaws 26 and 28, and extends substantially parallel with the median plane of the opening. TWith the thread holding devi-ces mounted upon the leoper arm, as shown in Fig. l, the thread cutting blade extends forwardly and upwardly from the thread holding devices so to enable the thread toY be severed by the operator after having been inserted in the thread holding jaws by an easy and convenient movement of the shoe.

With this construction of the thread cutand hclding devices, after the shoe has been manipulated to disengage the channel guide fram the channel, the shoe is moved upwardly and forwardly to locate the thread in position for insertion between the thread holding jaws 26 and 28, is then moved to theY right to insert the thread between the jaws and to carry the thread over the thread cutting blade 38, as shown in Fig. 1, and is then moved downwardlyv to draw the thread taut across 'the edge of the blade to sever thethrea'd.

Having explained of the invention, and having specifically described a. machine embodying the invention in its preferred form, what is claimed is:

1. Ashoe sewing machine, having, in combination, stitch forming devices including a hook needle and a looper., a thread holding device having opposed thread holding jaws yieldingly pressed toward each other, and means for'adjusti'ng independently the opening between the jaws for different sizes a hook needle and a looper,va thread holding Vdevice having opposed thread holding jaws yieldinglypressed toward each other, and

the nature and object means for relatively adjusting the jaws toward and from each other to vary the width of the opening between the jaws 'or different sizes of thread without changing the pressure exerted by the jaws on the thread.

3. A shoe sewing machine having, in combination, stitch forming devices including a hook needle and a looper, a thread holding device having opposed thread holding jaws yieldingly pressed toward each other, and adjustable means for limiting the relativemovement of said jaws toward each other.

4t. A shoe sewing machine, having, in combination, stitch forming mechanism including a hook needle and a looper, a block having a thread holding jaw formed thereon, a U-shaped spring plate embracing said block and having at the end of one arm a thread holding jaw arranged in opposed relation to the first jaw, and an adjusting screw threaded into the block and engaging the other arm of the spring plate to adjust the pressure of the jaws on the thread.

5. A shoe sewing' machine, having, in combination, stitch forming mechanism including a hook needle and a looper, a block having a thread holding jaw formed thereon, a U-shaped spring plate embracing said block and having at the end or' one arm a thread holding jaw arranged in opposed relation to the rst jaw, and an adjusting screw threaded into the block and engaging said arm to adjust the opening between the jaws for dilierent sizes of thread.

6. A shoe sewing machine, having, in combination, stitch forming mechanism including a hook needle and a looper, a block having a. thread holding jaw formed thereon, a U-shaped spring plate embracing said block and having at the end of one arm a thread holding jaw arranged in opposed relation to the iirst jaw, an adjusting' screw threaded into the block and engagingsaid arm to adjust the opening between the jaws for diiieerent sizes of thread, and an adjusting screw threaded into the block and engaging the other arm to adjust the opening between the jaws for different sizes of thread.

7. A shoe sewing machine, having, in combination, stitch forming mechanism including a hook needle and a looper, a blocl; having a thread holding jaw formed thereon, a U-shaped spring plate embracing said block and having at the. end of one arm a thread holding jaw arranged in opposed relation to the rst jaw, and a thread cutting blade which formed on said plate with its edge substantially parallel with the median plane of the opening between the jaws and located so that the thread is carried toward the same during the movement imparted thereto to insertthe thread between the jaws, the knife being directed in the direction of this thread movement.

8. A shoe sewing machine, having, in combination, stitch forming devices including a hook needle and a looper, a thread holding device having opposed thread holding jaws and comprising a spring plate upon which one of said jaws is formed, and a thread cutting blade formed on said plate with its edge substantially parallel with the median plane of the opening between the jaws and located so that the thread is carried toward the same during the movement imparted thereto to insert the thread between the the knife being directed in the direction of this thread movement.

9. shoe sewing machine having, in combination, stitch forming devices including a hook needle and a. looper, a thread holdingdevice having opposed thread holding jaws yieldingly pressed toward each other, adjustable means'for limiting the relative movement or" said jaws toward each other, and means for adjusting the force with said jaws are pressed toward each other.

l0. A. shoe sewing maching having, in combination, stitch forming devices including a hook needle and a looper, a thread holding device having opposed thread holding jaws, a spring plate upon which one of said jaws is formed, and an adjusting' screw engaging said spring plate to limit adjustably the movement of the jaw formed thereon toward the other jaw, and an adjusting screw engaging said spring plate to adjust the pressure with which the jaw Yformed thereon is pressed toward the other jaw.

ll. A shoe sewing machine, having, in combination, stitch forming mechanism including a hook needle and a looper, a block having a thread holding jaw formed thereon, a LLshaped spring plate embracing said bloclr and having at the end or' one arm a thread holding jaw arranged in opposed rela-tion to the first jaw, and means for relatively adjusting the arms of the spring plate.

THUMS H. SEELY. 

